What is Input Lag
The higher the refresh rate, the lower the input lag.
So, a 120Hz display will have essentially half the input lag in comparison to a 60Hz display since the picture gets updated more frequently and you can react to it sooner.
Pretty much all new high refresh rate gaming monitors have low enough input lag in relation to their refresh rate that the delay between your actions and the result on the screen will be imperceptible.
Therefore, if you want the fastest 240Hz or 360Hz gaming monitor available for competitive gaming, you should focus on its response time speed performance.
TVs usually have higher input lag than monitors.
For the best performance, look for a TV that has a native 120Hz refresh rate (not ‘effective’ or ‘fake 120Hz’ via framerate interpolation)!
It’s also very important to enable the ‘Game Mode’ on the TV. It bypasses certain image post-processing to reduce input lag.